Turbine electric power system with flywheel energy storage function and use method of turbine electric power system

Abstract

The invention provides a turbine electric power system with flywheel energy storage and a using method thereof, and belongs to the field of power systems of aviation aircrafts. Comprising a power supply module composed of a turbine motor set, a flywheel energy storage system and a battery system, the power supply module is controlled by an energy management system, power distribution of the turbine motor set, the flywheel energy storage system and the battery system is coordinated through flight working conditions, and after distribution, electric energy is distributed to an electrical load through an electrical bus. The turbine motor set, the flywheel energy storage system and the battery system work coordinately through the energy management system, the overrun risk of a turbine shaft engine caused by control response difference during load unloading is restrained, the situation that a battery excessively bears load fluctuation of a power system is avoided, the service time of the battery is prolonged, and the service life of the power system is prolonged. And the economical efficiency and the safety of the aircraft are improved.

Description

Technical Field

[0001] The present invention belongs to the field of power systems of aviation vehicles, and in particular relates to a turbine electric power system with flywheel energy storage and a use method thereof. Background Art

[0002] Although civil aviation carbon emissions account for only 2% of global energy-related carbon emissions each year, it is more difficult to decarbonize civil aviation than other modes of transportation, which has led to its carbon emissions growing faster than road, rail and sea transportation in recent decades. With the rise of the global low-carbon energy-saving wave, how to curb the growth trend of carbon emissions in the civil aviation industry has become the focus of the aviation industry in recent years. Among the series of development routes proposed, technical measures for the electrification of propulsion systems are included. As one of the important solutions for the electrification of propulsion systems, the turbo-electric power system solves the bottleneck problem brought about by the development of battery technology on the one hand, and takes into account the technical maturity and safety and airworthiness costs on the other hand, and has good market application prospects.

[0003] The turbo-electric power system consists of a traditional aviation gas turbine and electrical equipment such as batteries, generators, and motors. The use of aviation gas turbine generator sets and batteries to provide energy together effectively reduces the system's fuel consumption and improves system efficiency. However, there is a significant control response difference between the aviation gas turbine and electrical equipment in the turbo-electric power system. In the face of a rapid decrease in demand power, the aviation gas turbine has excess shaft power. The excess power will be converted into shaft kinetic energy, causing the aviation gas turbine shaft to over-rotate. Using batteries to quickly make up for / absorb the power gap / surplus power of the aviation gas turbine is considered an effective solution, but when using batteries to cope with the continuous fluctuations in the output power of the power system, the high-frequency switching of the charge and discharge state will greatly reduce the service life of the battery. Secondly, the battery life is an order of magnitude different from that of other equipment in the system. The use of battery control solutions will further compress the battery's on-wing time, seriously affecting the operation and airworthiness of the power system. Summary of the invention

[0004] Technical issues to be solved:

[0005] In order to avoid the shortcomings of the prior art, the present invention provides a turbo-electric power system with flywheel energy storage and a method of using the same, combining a flywheel structure with a traditional turbo-electric power system, and increasing the rotational inertia of the engine shaft by changing the mechanical operating structure, thereby eliminating the risk of low-pressure shaft over-rotation during the transition from high-level operation to low-level operation. At the same time, the energy storage function of the flywheel structure is utilized to optimize the energy management strategy of the aircraft during power changes, reduce the scheduling frequency of the battery, extend the service life of the battery, and reduce the operating cost of the turbo-electric power system. The present invention solves the problem of short battery service life in traditional turbo-electric power systems and the problem of low-pressure shaft over-rotation of turboshaft engines caused by differences in control response during large fluctuations in electrical loads.

[0006] The technical solution of the present invention is: a turbo-electric power system with flywheel energy storage, comprising a power supply module composed of a turbo-motor group, a flywheel energy storage system, and a battery system, wherein the power supply module is controlled by an energy management system, and the power distribution of the turbo-motor group, the flywheel energy storage system, and the battery system is coordinated according to flight conditions, and after distribution, the electric energy is distributed to the electrical load through an electrical bus;

[0007] The turbine generator set comprises a turboshaft engine, a second clutch, and a generator connected in sequence along the axial direction; one end of the low-pressure shaft of the turboshaft engine is connected to the generator through the second clutch, and the electric energy output by the generator is converted into direct current through a rectifier;

[0008] The flywheel energy storage system comprises a bidirectional permanent magnet motor and an improved flywheel structure placed in a vacuum box; the bidirectional permanent magnet motor is connected to the electrical bus through a bidirectional AC / DC rectifier, and the improved flywheel structure is coaxially mounted on its output shaft, and the output shaft is connected to the other end of the low-pressure shaft of the turboshaft engine through a first clutch;

[0009] The battery system is connected to the electrical bus through a converter;

[0010] The electrical bus isolates the generating end bus from the power consumption end bus through the power distribution unit. The generating end bus receives the electric energy from the turbine generator set, the battery system and the flywheel energy storage system, transmits it to the power consumption end bus through the cable, and then distributes it to the electrical load.

[0011] A further technical solution of the present invention is: the improved flywheel structure is a central hollow wheel with mass concentrated on the outer edge, and its moment of inertia satisfies:

[0012]

[0013] Where I is the moment of inertia, m is the overall mass of the improved flywheel structure, and R 1 To improve the inner diameter of the outer edge of the flywheel structure, R 2 To improve the outer diameter of the flywheel structure.

[0014] A further technical solution of the present invention is: the battery system is a fuel cell, connected to a fuel hydrogen storage tank and connected to an electrical bus through a unidirectional converter; the unidirectional converter is a unidirectional DC / DC converter or a unidirectional DC / AC inverter;

[0015] Or it is a lithium battery, which is connected to the electrical bus through a bidirectional converter; the bidirectional converter is a bidirectional DC / DC converter or a bidirectional DC / AC inverter.

[0016] A further technical solution of the present invention is: the electrical bus adopts a DC electrical bus, the battery system is connected to the DC electrical bus through a DC / DC converter, the flywheel energy storage system is connected to the DC electrical bus through an AC / DC rectifier, the turbine generator set is connected to the DC electrical bus through an AC / DC rectifier, and the electrical load is connected to the DC electrical bus through a DC / AC inverter, a DC / AC inverter and a DC / DC converter.

[0017] A further technical solution of the present invention is: the electrical load includes a high-voltage AC load, a medium-voltage AC load and a low-voltage DC load, the high-voltage AC load is connected to the electrical bus through a DC / AC inverter or an AC / AC converter, the medium-voltage AC load is connected to the electrical bus through a DC / AC inverter or an AC / AC converter, and the low-voltage DC load is connected to the electrical bus through a DC / DC converter or an AC / DC rectifier.

[0018] A further technical solution of the present invention is that the first clutch and the second clutch both have an engagement / disengagement function, and the clutch state is adjusted in real time according to the turbine shaft engine speed, flywheel speed and electrical load power demand.

[0019] A further technical solution of the present invention is: the energy management system performs dynamic power distribution, preferentially calls flywheel energy storage to suppress turbine shaft overspeed during takeoff, switches to battery charging mode during cruising, and optimizes the flywheel charge and discharge depth in real time to extend its mechanical life; it can ensure the coordination of transient power buffering of the flywheel energy storage system and the steady-state output of the turboshaft engine.

[0020] A method for using a turbine electric power system with flywheel energy storage:

[0021] When the aircraft is started on the ground: the first clutch and the second clutch are both disengaged, and the turboshaft engine is independently started to a self-sustaining state;

[0022] When the aircraft is in the ground slow-speed condition: the first clutch is engaged and the flywheel energy storage is started; at the same time, the turboshaft engine changes from a stable self-sustaining state to a speed-reducing state, and its mechanical energy is partially transferred to the flywheel energy storage system, resulting in a reduction in the speed of the engine's low-pressure shaft; as the flywheel speed gradually approaches the turboshaft engine's low-pressure shaft speed, the energy management system predicts the speed synchronization point in advance and instructs the throttle opening to gradually drop back to a constant value, entering the speed following state mode. After the flywheel energy storage system completes energy storage, it forms a joint self-sustaining state with the turboshaft engine;

[0023] During takeoff, climb, vertical takeoff and vertical landing: the throttle of the turboshaft engine is rapidly increased to the maximum continuous output to increase the power generation capacity; the first clutch is disengaged, and the flywheel energy storage system rapidly releases energy to supplement the power gap; as the power of the turboshaft engine rises to the maximum value and the energy of the flywheel energy storage system decreases, the battery system gradually increases the output power to ensure that the total power of the three is equal to the load demand; after the energy of the flywheel energy storage system is released, the output power of the battery system stops increasing and remains constant; during stable operation, the sum of the output power of the turbine generator set and the output power of the battery is equal to the power demand of the electrical load.

[0024] When the aircraft is in approach and rolling landing conditions: the first clutch is kept engaged, the flywheel energy storage system absorbs the excess kinetic energy of the turboshaft engine, and the battery is switched to charging mode; as the throttle continues to decrease, the speed of the turboshaft engine and the flywheel reaches a peak and then gradually decreases until it reaches a stable speed that matches the target power; during stable operation, the battery is in charging mode, and the output power of the turbine generator set is the sum of the electrical load power and the battery charging power;

[0025] The aircraft is in cruise condition: the first clutch is engaged and the flywheel rotates synchronously with the turbine shaft, the turbine generator set operates at full power and charges the battery;

[0026] A further technical solution of the present invention is: the aircraft has two situations in the cruise condition:

[0027] When the power consumption on the aircraft is lower than the power provided by the turbo-electric power system, the throttle of the turboshaft engine is rapidly reduced, and the rotational speed of the combination of the turbine motor group and the flywheel structure increases slightly; the subsequent engine throttle is not enough to maintain the increase in rotational speed and the flywheel energy storage system begins to output electrical energy to the outside, and the rotational speed of the combination of the turbine motor group and the flywheel structure gradually decreases; as the output power of the turbine motor group gradually matches the power consumption, the flywheel energy discharge state ends, the battery charging power increases slightly and then returns to the initial state, and the power system reaches a steady-state power balance again;

[0028] When the electrical power consumption on the aircraft is higher than the power provided by the turbo-electric power system, the throttle of the turboshaft engine increases rapidly, the clutch between the turboshaft engine and the flywheel energy storage system is quickly disconnected, and the generator in the flywheel energy storage system converts mechanical energy into electrical energy to quickly respond to power demand. The battery continues to be charged, but the charging power shows a downward trend; as the power of the turbine generator set gradually matches the electrical power consumption, the flywheel energy release state ends, the battery charging power gradually returns to its initial state, and the power system reaches a steady-state power balance again.

[0029] A further technical solution of the present invention is: the aircraft gives priority to flywheel energy storage when the energy management system power fluctuates, and calls the battery system only when the flywheel energy is insufficient; when the electrical load suddenly drops, the energy management system absorbs the excess kinetic energy of the turboshaft engine through the flywheel energy storage system; after the flywheel energy is exhausted, the battery system supplements the remaining demand with constant power to avoid high-frequency charging and discharging.

[0030] Beneficial Effects

[0031] The beneficial effects of the present invention are as follows: the present invention solves the industry problems of short battery life and high turbine overspeed risk in the aviation field through the deep synergy of flywheel energy storage technology and turbine electric power system, and has high dynamic response, long-term reliability and energy-saving and environmental protection characteristics, providing an innovative solution for the electrification of aviation propulsion systems. The specific effects are analyzed as follows:

[0032] 1. The present invention uses a flywheel energy storage system to quickly respond to transient power fluctuations (such as a sudden increase in load during takeoff or a sudden drop in load during landing), absorb or release energy to balance the power gap or surplus of the turboshaft engine, and suppress the speed fluctuation of the low-pressure shaft of the turboshaft, effectively avoiding the overspeed phenomenon caused by control response differences in traditional systems, and ensuring the safe operation of the aircraft power system.

[0033] 2. The flywheel energy storage system of the present invention bears short-term and high-frequency power fluctuations (such as transient power compensation and energy recovery), reduces the charging and discharging frequency of lithium batteries or fuel cells, and avoids capacity attenuation and shortened life of the battery due to high-frequency switching.

[0034] 3. The improved flywheel structure of the present invention adopts a hollow wheel disc design with concentrated outer mass, which increases the moment of inertia by 20% to 35% compared with the traditional solid flywheel under the same mass, and enhances the inertia compensation capability of the turboshaft engine. Combining the vacuum box environment and magnetic suspension bearing technology, the flywheel rotation loss is reduced to ≤2%, and the energy storage efficiency reaches more than 95%.

[0035] 4. The energy management system of the present invention dynamically allocates power according to the flight phase:

[0036] Take-off / climb phase: The flywheel releases stored energy first, the turboshaft engine gradually increases to full power, and the battery only supplements the remaining gap;

[0037] Cruise phase: the flywheel and turbine shaft idle synchronously, the turbine drives the load at full power and charges the battery;

[0038] Landing phase: The flywheel absorbs excess kinetic energy and the battery switches to charging mode.

[0039] 5. The system of the present invention reduces the frequent power adjustment of the turboshaft engine and reduces fuel consumption and carbon emissions through the transient buffering capacity of the flywheel energy storage. At the same time, the flywheel and the battery back up each other, providing emergency power redundancy in the event of battery failure, ensuring the safety of power supply in critical flight stages (such as landing). BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of the working principle of a turbine electric power system with flywheel energy storage in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the working principle of another turbine electric power system with flywheel energy storage in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of an improved flywheel structure in an embodiment of the present invention;

[0043] Figure 4 Comparison chart of simulation results when constant speed control is selected as the engine control law.

[0044] Description of the accompanying drawings: 1. flywheel energy storage system, 2. vacuum box, 3. bidirectional permanent magnet motor, 4. bidirectional AC / DC rectifier, 5. improved flywheel structure, 6. first clutch, 7. turbine motor group, 8. turboshaft engine, 9. turboshaft engine high pressure shaft, 10. turboshaft engine low pressure shaft, 11. second clutch, 12. generator, 13. unidirectional AC / DC rectifier, 14. battery system, 15. hydrogen fuel cell, 16. hydrogen storage tank, 1 7. First DC / DC converter, 18. DC electrical bus, 19. Third power distribution unit, 20. Second power distribution unit, 21. First power distribution unit, 22. Power generation end bus, 23. Cable, 24. Power consumption end bus, 25. Fourth power distribution unit, 26. Sixth power distribution unit, 27. Fifth power distribution unit, 28. Second DC / DC converter, 29. Second DC / AC inverter, 30. Electrical load, 31. First DC / AC inverter. DETAILED DESCRIPTION

[0045] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0046] In view of the problem of short battery service life in traditional turbo-electric power systems and the problem of over-rotation of the low-pressure shaft of the turbo-shaft engine caused by the difference in control response during large fluctuations in electrical load, the present invention provides a turbo-electric power system with flywheel energy storage, including a power supply module composed of a turbo-motor group, a flywheel energy storage system, and a battery system. The power supply module is controlled by an energy management system, and the power distribution of the turbo-motor group, the flywheel energy storage system, and the battery system is coordinated according to flight conditions. After distribution, the electric energy is distributed to the electrical load through an electrical bus; the turbo-motor group includes a turbo-shaft engine, a second clutch, and a second clutch connected in sequence along the axial direction. a generator; one end of the low-pressure shaft of the turboshaft engine is connected to the generator through a second clutch, and the electric energy output by the generator is converted into direct current through a rectifier; the flywheel energy storage system includes a bidirectional permanent magnet motor and an improved flywheel structure placed in a vacuum box; the bidirectional permanent magnet motor is connected to the electrical bus through a bidirectional AC / DC rectifier, and an improved flywheel structure is coaxially mounted on its output shaft, and the output shaft is connected to the other end of the low-pressure shaft of the turboshaft engine through a first clutch; the battery system is connected to the electrical bus through a converter; the electrical bus isolates the generating end bus from the power consumption end bus through a distribution unit (DPU, Distributed Power Unit), and the generating end bus receives the electric energy of the turbine generator set, the battery system and the flywheel energy storage system, and distributes it to the electrical load after transmitting it to the power consumption end bus through a cable.

[0047] Specifically, a bidirectional converter or a unidirectional converter is provided between the battery system and the power distribution unit, the bidirectional converter is a bidirectional DC / DC converter or a bidirectional DC / AC inverter, and the unidirectional converter is a unidirectional DC / DC converter or a unidirectional DC / AC inverter.

[0048] Specifically, the electrical load includes a high-voltage AC load, a medium-voltage AC load and a low-voltage DC load. The high-voltage AC load is connected to the electrical bus through a DC / AC inverter or an AC / AC converter, the medium-voltage AC load is connected to the electrical bus through a DC / AC inverter or an AC / AC converter, and the low-voltage DC load is connected to the electrical bus through a DC / DC converter or an AC / DC rectifier.

[0049] At the same time, the present invention proposes a method for using a turbo-electric power system with flywheel energy storage, which designs the clutch connection / disconnection logic based on the flight stage (such as ground start, slow speed, and cruising) to ensure that the speed of the flywheel and the turboshaft engine are synchronized to avoid mechanical shock. And through a phased power distribution strategy (such as flywheel priority energy release during takeoff and battery charging during cruising), real-time state recognition and decision-making are achieved through an intelligent power distribution unit.

[0050] The above technical solution is further described below in conjunction with the accompanying drawings:

[0051] In one embodiment, referring to Figure 1 As shown, an aircraft turbo-electric power system with flywheel energy storage includes: a turbine generator set 7, a battery system 14, a flywheel energy storage system 1, a power electronic converter, an electrical bus and an electrical load 30. The electrical bus is connected to the turbine generator set 7, the battery system 14, the flywheel energy storage system 1 and the electrical load 30 through the power electronic converter, respectively. The turbine generator set 7, the battery system 14 and the flywheel energy storage system 1 provide power for the electrical load 30. The turbine generator set 7 and the battery system 14 mainly provide stable power output, and the flywheel energy storage system 1 mainly compensates for the transient power fluctuation of the electrical bus.

[0052] Specifically, the turbine generator set 7 includes a turboshaft engine 8, a generator 12, a second clutch 11 and a one-way AC / DC rectifier 13. The low-pressure shaft 10 of the turboshaft engine 8 is connected to the generator 12 through the second clutch 11. The generator 12 is driven by the turboshaft engine low-pressure shaft 10 to generate electricity. The one-way AC / DC rectifier 13 rectifies the electric energy generated by the generator 12 and transmits it to the electrical bus.

[0053] Specifically, the flywheel energy storage system 1 includes an improved flywheel structure 5, a bidirectional permanent magnet motor 3 coaxial with the improved flywheel structure 5, a bidirectional AC / DC rectifier 4 and a vacuum box 2. The improved flywheel structure 5 and the bidirectional permanent magnet motor 3 are placed in the vacuum box 2. The improved flywheel structure 5 is driven by the turboshaft engine 8 in the turbine generator group 7 through the first clutch 6 to rotate and store energy. The bidirectional permanent magnet motor 3 generates electricity under the inertial rotation drive of the improved flywheel structure 5 or converts the electrical energy obtained from the bidirectional AC / DC rectifier 4 into mechanical energy of the improved flywheel structure 5. The bidirectional AC / DC rectifier 4 rectifies the electrical energy generated by the bidirectional permanent magnet motor 3 and transmits it to the electrical bus or transmits excess power of the electrical bus to the bidirectional permanent magnet motor 3.

[0054] Specifically, the electrical bus includes a distribution unit, a cable 23, a generating end bus 22 and a power consumption end bus 24. The distribution unit is directly connected to the bus. The first distribution unit 21, the second distribution unit 20, and the third distribution unit 19 respectively introduce the electric energy generated by the flywheel energy storage system 1, the turbine generator set 7, and the battery system 14 into the generating end bus 22. The cable 23 transmits the electric energy on the generating end bus 22 to the power consumption end bus 24. The power consumption end bus 24 redistributes the electric energy to each electrical load 30 via the fourth distribution unit 25, the fifth distribution unit 27, and the sixth distribution unit 26.

[0055] Specifically, the battery system 14 uses lithium batteries; the lithium batteries are connected to the electrical bus through the first DC / DC converter 17.

[0056] Specifically, in order to reduce the mass and internal resistance loss of the electrical bus, the electrical bus adopts a DC electrical bus 18, the battery system 14 is connected to the DC electrical bus 18 through a first DC / DC converter 17, the flywheel energy storage system 1 is connected to the DC electrical bus 18 through a bidirectional AC / DC rectifier 4, the turbine generator set 7 is connected to the DC electrical bus 18 through a unidirectional AC / DC rectifier 13, and the electrical load 30 is connected to the DC electrical bus 18 through a second DC / DC converter 28, a second DC / AC inverter 29 and a first DC / AC inverter 31.

[0057] Specifically, a second clutch 11 with a connection / disconnection function is provided between the turboshaft engine 8 and the generator 12 .

[0058] Specifically, a first clutch 6 with a connection / disconnection function is provided between the turboshaft engine 8 and the flywheel energy storage system 1 .

[0059] Specifically, the generator 12 is a permanent magnet synchronous generator, which is connected to a generator controller, and the generator controller is integrated with a unidirectional AC / DC rectifier 13 in the turbine generator set 7 .

[0060] Specifically, the bidirectional permanent magnet motor 3 is a permanent magnet synchronous motor, the bidirectional permanent magnet motor is connected to a bidirectional motor controller, and the bidirectional motor controller is integrated with the bidirectional AC / DC rectifier 4 in the flywheel energy storage system 1 .

[0061] Specifically, the power distribution unit includes an intelligent controller and an actuator. The intelligent controller can identify the system operation status and make corresponding power distribution decisions. The actuator quickly executes node access / disconnection actions according to the power distribution decisions.

[0062] In one embodiment, referring to Figure 3 As shown, the main features of the improved flywheel structure 5 are that the flywheel is integrally formed and the mass is concentrated on the outer edge of the flywheel. The inner support structure of the wheel disc adopts hollowing treatment to reduce weight to ensure the overall structural strength requirements of the flywheel. The improved flywheel structure is connected and fixed to the rotating shaft of the bidirectional permanent magnet motor through a keyway structure.

[0063] The calculation formula of the moment of inertia of the improved flywheel structure can be approximated as the calculation formula of a hollow cylinder, which is as follows:

[0064]

[0065] Where: I is the moment of inertia, m is the overall mass of the flywheel structure, R 1 is the inner diameter of the flywheel structure, R 2 is the outer diameter of the flywheel structure.

[0066] In one embodiment, referring to Figure 2 As shown, this embodiment provides a turbine electric power system with flywheel energy storage, including: a turbine generator set 7 for providing power for an aircraft, a battery system 14, a flywheel energy storage system 1, a DC electrical bus 18, a power electronic converter, and an electrical load 30. The DC electrical bus 18 is connected to the turbine generator set 7, the battery system 14, the flywheel energy storage system 1, and the electrical load 30 through a power electronic converter, respectively. The turbine generator set 7 and the battery system 14 provide power to the electrical load 30, and the flywheel energy storage system 1 mainly supplements power for the DC electrical bus 18 or absorbs the remaining power of the DC electrical bus 18 in a short period of time.

[0067] Specifically, the turbine generator set 7 includes a turboshaft engine 8, a generator 12, a second clutch 11 and a one-way AC / DC rectifier 13. The turboshaft engine low-pressure shaft 10 is connected to the second generator 12 through the second clutch 11. The generator 12 is driven by the turboshaft engine low-pressure shaft 10 to generate electricity. The one-way AC / DC rectifier 13 rectifies the electric energy generated by the generator 12 and transmits it to the DC electrical bus 18.

[0068] Specifically, the flywheel energy storage system 1 includes an improved flywheel structure 5, a bidirectional permanent magnet motor 3 coaxial with the improved flywheel structure 5, a bidirectional AC / DC rectifier 4 and a vacuum box 2. The improved flywheel structure 5 and the bidirectional permanent magnet motor 3 are arranged in the vacuum box 2, and the improved flywheel structure 5 is driven by the turboshaft engine 8 in the turbine generator group 7 through the first clutch 6 to rotate and store energy. The bidirectional permanent magnet motor 3 generates electricity under the inertial rotation drive of the improved flywheel structure 5, and the bidirectional AC / DC rectifier 4 rectifies the electric energy generated by the bidirectional permanent magnet motor 3 and transmits it to the DC electrical bus 18.

[0069] Specifically, the battery system 14 includes a hydrogen fuel cell 15, a hydrogen storage tank 16 and a first DC / DC converter 17. The hydrogen storage tank 16 supplies hydrogen to the hydrogen fuel cell 15. The DC power generated by the hydrogen fuel cell 15 is boosted and transmitted to the DC electrical bus 18 through the first DC / DC converter 17. The DC electrical bus 18 includes a distribution unit, a cable 23, a generating end bus 22 and a power consumption end bus 24. The distribution unit is directly connected to the generating end bus 22 and the power consumption end bus 24. The distribution unit introduces the electric energy generated by the turbine generator set 7, the hydrogen fuel cell system 14 and the flywheel energy storage system 1 into the generating end bus 22. The cable 23 transmits the electric energy on the generating end bus 22 to the power consumption end bus 24. The power consumption end bus 24 redistributes the electric energy to the electrical load 30 through the distribution unit.

[0070] Specifically, the DC electrical bus 18 adopts a DC bus, the hydrogen fuel cell 15 is connected to the DC electrical bus 18 through a first DC / DC converter 17, the flywheel energy storage system 1 is connected to the DC electrical bus 18 through a bidirectional AC / DC rectifier 4, the turbine generator set 7 is connected to the DC electrical bus 18 through an AC / DC rectifier 13, and the electrical load 30 is connected to the electrical bus through a first DC / AC inverter 25, a second DC / AC inverter 27 and a second DC / DC converter 26.

[0071] Specifically, the flywheel energy storage system 1 works in coordination with the turbine generator set 7 and the battery system 14 and is coordinated by an energy management system, which includes a power generation management subsystem, a power distribution management subsystem and a load management subsystem. The power generation management subsystem provides power for the aircraft and electricity for the equipment, the power distribution management subsystem controls the connection / disconnection of each power generation and consumption equipment to the DC electrical bus 18, and the load management subsystem performs power management and load limitation on high-power power consumption equipment.

[0072] Specifically, the electrical load 30 includes a high-voltage AC load, a medium-voltage AC load and a low-voltage DC load. The high-voltage AC load is connected to the DC electrical bus 18 through a first DC / AC inverter 31, the medium-voltage AC load is connected to the DC electrical bus 18 through a second DC / AC inverter 29, and the low-voltage DC load is connected to the DC electrical bus 18 through a second DC / DC converter 28.

[0073] Specifically, a second clutch 11 with a connection / disconnection function is provided between the turboshaft engine 8 and the generator 12 in the turbine generator set 7.

[0074] Specifically, a first clutch 6 with a connection / disconnection function is provided between the turboshaft engine 8 and the flywheel energy storage system 1 .

[0075] Specifically, the engagement / disengagement function of the second clutch 11 and the first clutch 6 is realized by a clutch actuation control system, and the clutch actuation control system includes a control instruction processor, a hydraulic actuator, a hydraulic oil tank, and a hydraulic pipeline.

[0076] Specifically, the generator 12 is a permanent magnet synchronous generator, which is connected to a generator controller, and the generator controller is integrated with the unidirectional AC / DC rectifier 13 .

[0077] Specifically, the bidirectional permanent magnet motor 3 is a permanent magnet synchronous motor, the bidirectional permanent magnet motor 3 is connected to a bidirectional motor controller, and the bidirectional motor controller is integrated with the bidirectional AC / DC rectifier 4 in the flywheel energy storage system 1 .

[0078] Specifically, the power distribution unit includes an intelligent controller and an actuator. The intelligent controller can identify the system operation status and make corresponding power distribution decisions. The actuator quickly executes node access / disconnection actions according to the power distribution decisions.

[0079] In one embodiment, a method for using the above-mentioned turbine electric power system with flywheel energy storage is as follows:

[0080] When the aircraft is started on the ground, the first clutch 6 between the turbine generator set 7 and the flywheel energy storage system 1, and the clutch between the turboshaft engine 8 and the generator 12 in the turbine generator set 7 are disengaged, and the flywheel body 5 and the generator 12 in the turbine generator set 7 maintain an initial static state to ensure the rapid start of the turboshaft engine 8 and enter a self-sustaining state; during this period, the flywheel energy storage system 1, the hydrogen fuel cell system 14 and the turbine generator set 7 neither output energy to the electrical bus 18 nor absorb energy from the electrical bus 18.

[0081] When the aircraft is in the ground slow-speed condition, the first clutch 6 between the turbine generator set 7 and the flywheel energy storage system 1 is connected, the flywheel energy storage system 1 enters the rapid energy storage state, the turboshaft engine 8 temporarily enters the speed reduction state from the stable self-sustaining state, and the throttle of the turboshaft engine 8 increases rapidly to compensate for the additional energy demand generated by the energy storage of the flywheel energy storage system 1 and the speed fluctuation of the turboshaft engine low-pressure shaft 10; when the speed of the improved flywheel structure 5 and the turboshaft engine low-pressure shaft 10 gradually approaches, the engine throttle opening will gradually fall back in advance and remain constant. And the throttle opening in the constant state is higher than the throttle opening in the self-sustaining state during the starting phase. The control response delay of the turboshaft engine 8 will gradually synchronize the speed of the flywheel body 5 with the low-pressure shaft 10 of the turboshaft engine. The flywheel energy storage system 1 ends energy storage and switches to the follow-up holding mode. The turbine generator set 7 and the flywheel energy storage system 1 cooperate to enter a stable self-sustaining state. During this period, the flywheel energy storage system 1 neither outputs energy to the electrical bus 18 nor absorbs energy from the electrical bus 18. All power requirements are met by the hydrogen fuel cell system 14 and the turbine generator set 7.

[0082] When the aircraft is in the take-off, climb, vertical take-off and vertical landing conditions, in the initial stage, when the instantaneous power demand of the electrical load 30 is much greater than the power provided by the turbine generator set 7, the throttle of the turboshaft engine 8 is first increased rapidly, and the energy management system and the clutch actuation control system work in coordination, firstly, the clutch between the turboshaft engine 8 and the flywheel energy storage system 1 is quickly disengaged, so that the flywheel energy storage system 1 quickly releases energy to supplement the power gap, and as the power response of the turboshaft engine 8 gradually increases and reaches the maximum continuous output value and the energy of the flywheel energy storage system 1 gradually decreases, the fuel cell system 14 also gradually increases the output power for power supplement. During this period, the sum of the power output of the flywheel energy storage system 1, the turbine generator set 7 and the fuel cell system 14 is equal to the power demand of the electrical load 30; when the energy of the flywheel energy storage system 1 is gradually released, the output power of the hydrogen fuel cell system 14 stops increasing and enters a constant state. During stable operation, the sum of the output power of the turbine generator set 7 and the output power of the hydrogen fuel cell system 14 is equal to the power demand of the electrical load 30.

[0083] When the aircraft is in the approach and roll-out landing conditions, the power of the electrical load 30 is greatly reduced in the initial stage, and the power provided by the turbine motor group 7 and the hydrogen fuel cell system 14 is much greater than the power required by the electrical load 30, the throttle of the turboshaft engine 8 is first rapidly reduced, the hydrogen supply of the hydrogen storage tank 16 in the hydrogen fuel cell system 14 is also gradually reduced, and the output power of the hydrogen fuel cell system 14 is gradually reduced; the energy management system works in coordination with the clutch actuation control system, and the first clutch 6 between the turbine motor group 7 and the flywheel energy storage system 1 will continue to remain in the connected state to prevent the turboshaft engine low-pressure shaft 10 from over-rotating due to excess power during the control response lag period; during the control response lag period, most of the power demand of the electrical load 30 is provided by the hydrogen fuel cell system 14, and a small part of the power demand is provided by the turbine motor group 7, and the flywheel energy storage system 1 only absorbs power but does not output power; as the throttle gradually decreases, the turboshaft engine low-pressure shaft 10 is automatically turned off, and the power demand of the electrical load 30 is greatly reduced. After the speed of the low-pressure shaft 10 and the flywheel body 5 rises to the peak value, it begins to gradually decrease. The first clutch 6 will be disengaged when the speed reaches the peak value, and the low-pressure shaft 10 of the turboshaft engine and the flywheel body 5 will enter a separate and independent operation state. As the throttle is reduced, the turboshaft engine 8 will gradually enter a stable working state that matches the output power; if the throttle of the turboshaft engine 8 reaches the minimum self-sustaining state, and the power provided by the turbine motor group 7 and the hydrogen fuel cell system 14 is still greater than the power required by the electrical load 30, the hydrogen supply of the hydrogen fuel cell system 14 will continue to be reduced to reduce its output power. During this period, the flywheel energy storage system 1 will absorb the excess power generated by the hydrogen fuel cell system 14 from the electrical bus 18; during stable operation, the power demand of the electrical load 30 will be met by the turbine motor group 7 and the hydrogen fuel cell system 14 together or by the hydrogen fuel cell system 14 alone, depending on the gap between the actual power demand and the design parameters of the power system.

[0084] In this embodiment, when the aircraft is cruising normally, the first clutch 6 between the flywheel energy storage system 1 and the turbine generator set 7 is engaged and maintains synchronous rotation, and the flywheel energy storage system 1 does not output power to the electrical bus 18. At this time, the turbine generator set 7 maintains a low power level operation, and the hydrogen fuel cell system 14 operates at full power. The power demand of the electrical load 30 will be met by the turbine generator set 7 and the hydrogen fuel cell system 14.

[0085] In this embodiment, during the aircraft cruising, when the power consumption on the aircraft is lower than the power provided by the turbo-electric power system, the throttle of the turboshaft engine 8 is rapidly reduced, and the hydrogen fuel cell system 14 maintains the full power operation state unchanged. A part of the short-term excess mechanical energy of the turboshaft engine 8 is transmitted to the flywheel energy storage system 1 through the first clutch 6 for energy storage, and the other part is converted into electrical energy by the generator 12 in the turbo-motor group 7, and transmitted to the power generation end bus 22 through the second power distribution unit 20. The electrical energy generated by the hydrogen fuel cell system 14 is transmitted to the power generation end bus 22 through the third power distribution unit 19. After the power of the power generation end bus 22 meets the demand of the electrical load 30 first, the remaining power is transmitted to the improved flywheel structure 5 through the first power distribution unit 21, the bidirectional AC / DC rectifier 4 and the bidirectional permanent magnet motor 3 for energy storage. As the output power of the turbo-motor group 7 and the output power of the hydrogen fuel cell system 14 gradually match the power consumption, the energy storage state of the flywheel energy storage system 1 ends, and the power system reaches a power balance state again.

[0086] In this embodiment, during the cruising of the aircraft, when the electrical power consumption on the aircraft is higher than the power provided by the turbo-electric power system, the throttle of the turboshaft engine 8 is rapidly increased, the hydrogen fuel cell system 14 maintains the full-power operating state unchanged, the first clutch 6 between the turboshaft engine 8 and the flywheel energy storage system 1 is quickly disconnected, and the reversible motor / generator 3 in the flywheel energy storage system 1 converts mechanical energy into electrical energy to quickly respond to power demand; when the throttle of the turboshaft engine 8 is increased so that the turbo-generator group 7 can completely make up for the power gap, the energy release state of the flywheel energy storage system 1 ends. At this time, the output power of the turbo-generator group 7 and the hydrogen fuel cell system 14 is equal to the required power of the electrical load 30, and the power system enters a stable state again. Subsequently, the first clutch 6 will wait for an opportunity to connect, so that the flywheel energy storage system 1 and the turbo-generator group 7 can operate together again.

[0087] Specifically, the energy management system includes a power generation management system, a load management system and a power distribution management system. The power generation management subsystem provides aircraft power and equipment electricity. The power distribution management subsystem controls the connection / disconnection of each power generation and consumption equipment to the electrical bus. The load management subsystem performs power management and load limitation on high-power power consumption equipment.

[0088] Specifically, the clutch actuation control system includes a control instruction processor, a hydraulic actuator, a hydraulic oil tank, and a hydraulic pipeline.

[0089] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A turbine electric power system with flywheel energy storage, characterized in that: It includes a power supply module composed of a turbine generator set, a flywheel energy storage system, and a battery system. The power supply module is controlled by an energy management system, and the power distribution of the turbine generator set, the flywheel energy storage system, and the battery system is coordinated according to the flight conditions. After the distribution, the electric energy is distributed to the electrical load through the electrical bus. The turbine generator set comprises a turboshaft engine, a second clutch, and a generator connected in sequence along the axial direction; one end of the low-pressure shaft of the turboshaft engine is connected to the generator through the second clutch, and the electric energy output by the generator is converted into direct current through a rectifier; The flywheel energy storage system comprises a bidirectional permanent magnet motor and an improved flywheel structure placed in a vacuum box; the bidirectional permanent magnet motor is connected to the electrical bus through a bidirectional AC / DC rectifier, and the improved flywheel structure is coaxially mounted on its output shaft, and the output shaft is connected to the other end of the low-pressure shaft of the turboshaft engine through a first clutch; The battery system is connected to the electrical bus through a converter; The electrical bus isolates the generating end bus from the power consumption end bus through the power distribution unit. The generating end bus receives the electric energy from the turbine generator set, the battery system and the flywheel energy storage system, transmits it to the power consumption end bus through the cable, and then distributes it to the electrical load.

2. A turbine electric power system with flywheel energy storage according to claim 1, characterized in that: The improved flywheel structure is a central hollow wheel with mass concentrated on the outer edge, and its moment of inertia satisfies: Wherein, I is the moment of inertia, m is the overall mass of the improved flywheel structure, R1 is the inner diameter of the outer edge of the improved flywheel structure, and R2 is the outer diameter of the improved flywheel structure.

3. A turbine electric power system with flywheel energy storage according to claim 1, characterized in that: The battery system is a fuel cell, connected to a fuel hydrogen storage tank and connected to an electrical bus through a unidirectional converter; the unidirectional converter is a unidirectional DC / DC converter or a unidirectional DC / AC inverter; Or it is a lithium battery, which is connected to the electrical bus through a bidirectional converter; the bidirectional converter is a bidirectional DC / DC converter or a bidirectional DC / AC inverter.

4. A turbine electric power system with flywheel energy storage according to claim 1, characterized in that: The electrical bus adopts a DC electrical bus, the battery system is connected to the DC electrical bus through a DC / DC converter, the flywheel energy storage system is connected to the DC electrical bus through an AC / DC rectifier, the turbine generator set is connected to the DC electrical bus through an AC / DC rectifier, and the electrical load is connected to the DC electrical bus through a DC / AC inverter, a DC / AC inverter and a DC / DC converter.

5. The turbine electric power system with flywheel energy storage according to claim 1, characterized in that: The electrical load includes a high-voltage AC load, a medium-voltage AC load and a low-voltage DC load. The high-voltage AC load is connected to the electrical bus through a DC / AC inverter or an AC / AC converter, the medium-voltage AC load is connected to the electrical bus through a DC / AC inverter or an AC / AC converter, and the low-voltage DC load is connected to the electrical bus through a DC / DC converter or an AC / DC rectifier.

6. The turbine electric power system with flywheel energy storage according to claim 1, characterized in that: The first clutch and the second clutch both have an engagement / disengagement function, and the clutch state is adjusted in real time according to the turbine shaft engine speed, flywheel speed and electrical load power demand.

7. The turbine electric power system with flywheel energy storage according to claim 1, characterized in that: The energy management system performs dynamic power distribution, preferentially uses flywheel energy storage to suppress turbine shaft over-rotation during takeoff, switches to battery charging mode during cruising, and optimizes the flywheel charge and discharge depth in real time to extend its mechanical life; It can ensure the coordination between the transient power buffering of the flywheel energy storage system and the steady-state output of the turboshaft engine.

8. A method for using the turbine electric power system with flywheel energy storage according to any one of claims 1 to 7, characterized in that: When the aircraft is started on the ground: the first clutch and the second clutch are both disengaged, and the turboshaft engine is independently started to a self-sustaining state; When the aircraft is in the ground slow-speed condition: the first clutch is engaged and the flywheel energy storage is started; at the same time, the turboshaft engine changes from a stable self-sustaining state to a speed-reducing state, and its mechanical energy is partially transferred to the flywheel energy storage system, resulting in a reduction in the speed of the engine's low-pressure shaft; as the flywheel speed gradually approaches the turboshaft engine's low-pressure shaft speed, the energy management system predicts the speed synchronization point in advance and instructs the throttle opening to gradually drop back to a constant value, entering the speed following state mode. After the flywheel energy storage system completes energy storage, it forms a joint self-sustaining state with the turboshaft engine; During the aircraft takeoff, climb, vertical takeoff and vertical landing conditions: the turboshaft engine throttle is rapidly increased to the maximum continuous output to increase the power generation capacity; the first clutch is disengaged, and the flywheel energy storage system rapidly releases energy to supplement the power gap; as the turboshaft engine power rises to the maximum value and the flywheel energy storage system energy decreases, the battery system gradually increases the output power to ensure that the total power of the three is equal to the load demand; after the flywheel energy storage system energy is fully released, the battery system output power stops increasing and remains constant; during stable operation, the sum of the turbine generator set output power and the battery output power is equal to the electrical load demand power; When the aircraft is in approach and rolling landing conditions: the first clutch is kept engaged, the flywheel energy storage system absorbs the excess kinetic energy of the turboshaft engine, and the battery is switched to charging mode; as the throttle continues to decrease, the speed of the turboshaft engine and the flywheel reaches a peak and then gradually decreases until it reaches a stable speed that matches the target power; during stable operation, the battery is in charging mode, and the output power of the turbine generator set is the sum of the electrical load power and the battery charging power; The aircraft is in cruising condition: the first clutch is engaged and the flywheel rotates synchronously with the turbine shaft, the turbine generator set runs at full power and charges the battery.

9. The method of use according to claim 8, characterized in that: There are two situations of the aircraft in cruise condition: When the power consumption on the aircraft is lower than the power provided by the turbo-electric power system, the throttle of the turboshaft engine is rapidly reduced, and the rotational speed of the combination of the turbine motor group and the flywheel structure increases slightly; the subsequent engine throttle is not enough to maintain the increase in rotational speed and the flywheel energy storage system begins to output electrical energy to the outside, and the rotational speed of the combination of the turbine motor group and the flywheel structure gradually decreases; as the output power of the turbine motor group gradually matches the power consumption, the flywheel energy discharge state ends, the battery charging power increases slightly and then returns to the initial state, and the power system reaches a steady-state power balance again; When the electrical power consumption on the aircraft is higher than the power provided by the turbo-electric power system, the throttle of the turboshaft engine increases rapidly, the clutch between the turboshaft engine and the flywheel energy storage system is quickly disconnected, and the generator in the flywheel energy storage system converts mechanical energy into electrical energy to quickly respond to power demand. The battery continues to be charged, but the charging power shows a downward trend; as the power of the turbine generator set gradually matches the electrical power consumption, the flywheel energy release state ends, the battery charging power gradually returns to its initial state, and the power system reaches a steady-state power balance again.

10. The method of use according to claim 8, characterized in that: The aircraft prioritizes flywheel energy storage when the energy management system power fluctuates, and calls on the battery system only when the flywheel energy is insufficient; when the electrical load suddenly drops, the energy management system absorbs excess kinetic energy of the turboshaft engine through the flywheel energy storage system; after the flywheel energy is exhausted, the battery system supplements the remaining demand with constant power to avoid high-frequency charging and discharging.

Images